"Do you value your life? Do you think that your family and friends are important to you? If they are, then you should never think of changing yourself. Otherwise, you will lose everything that is precious to you."

Since her arrival at Mitakihara Middle School, she is immediately depicted as being very intelligent, athletic, distant, and cold. It is revealed in episode four that she is only like this because she has seen so much suffering during her tenure as a magical girl. Because of this, she does not want Madoka Kaname to become a magical girl and tries to do anything in order to stop her from making a wish with Kyubey, going as far as to attempt to injure and even kill the cat-like creature. Despite her cold attitude towards others, she still very much cares for Madoka as it is her sole objective to protect her due to the countless amount of blood, sweat, and tears she has shed over her jumps in time.

Otaku Trivia:

1) At a Nitro+ Q&A Panel it was revealed that Homura went through almost 100 timelines.

2) Homura is the strongest of the magical girls as long as no one discovers the nature of her power